var one = 1;
let two = 2;
const three = 3;

// var
// Function scoped 函数全局作用域 第10行定义 第一行就能用
// Can be changed in scope
// Available before declaration

// let
// block scoped
// Can be changed in scope
// Only available after declaration

// const like let not changed

// const by default
// let in loops
// var no use
console.log(three)
